Oxford University Cave Club

Expedition to Northern Spain July / August 1973

Interim Report

The 1973 Oxford University Cave Club expedition spent a total of five
weeks in the field, and is pleased to be able to report the successful
extension and exploration of several significant caves within the area
bounded by the Rio de las Cabras and the Rio Sella.

The main body of the expedition left Oxford on July 4 and arrived in
the Llanes region in Asturias two days later, without undue
difficulty. It proved necessary to effect repair to the wheel hubs of
the trailer in the area of Poitiers. Compared to the experiences of
previous expeditions, however, the travelling, in both directions, was
relatively trouble free.

It was decided that, although the Cueva Negra had the greatest
theoretical potential, a campsite at Rales would be preferable, as it
would provide both a cave within walking distance and better access to
the town of Llanes. Accordingly, we negotiated with the owners of the
bar at Rales, and were presented with a rather superior field adjacent
to the Rio de las Cabras, the eastern boundary of the chosen area.
Charging facilities for caving lights were also arranged with the
owners of the bar. The camping aspect of the expedition was very
successful; the villagers of Rales proved to be as friendly and
interested as those of El Mazuco, where three previous expeditions had
been based. Indeed, by the time we left the village, an unofficial
speleological group, composed of the local youth, was presenting us
with information on new cave entrances each day.

The bulk of the expedition's attention was in fact devoted to the
cave, or caves, of Rales. We were rewarded by the discovery of a
system with a total passage length of between 2-2.5 kilometres. The
Cueva de Fuentica, immediately behind the village,had been looked at
by the 1972 reconnaissance expedition. There is evidence that Spanish
cavers have investigated the entrance series, which is dry. The first
three days of actual caving were spent or exploring the streamway,
using the maypole to scale the two pitches which were met. The
streamway of Fuentica provides some very enjoyable caving. It is
impressively decorated and contains sufficient obstacles to ensure
that these formations remain protected. It was therefore with some
chagrin that we found the character of the cave dramatically altered
above the second pitch. Progress was halted by a low wet crawl blocked
with small boulders. However on the same afternoon, we were taken up
the valley behind the village to be shown an enormous cave entrance,
taking a stream similar in size to that in Fuentica, and a cliff
behind this sink with numerous entrances, one of which introduced the
same stream. A link between the Pozo del Molino, the large sink, and
Fuentica was subsequently effected by removing a handful of boulders
at the end of the cave and immediately entering the crawl at the top
of Fuentica. Investigation of the resurgence, known as Samoreli,
revealed a short cave containing a chamber of impressive dimensions.
The sump yielded nothing to free diving attempts. This cave could also
be entered directly from the surface via a 10 metre pitch.

Considerable time and energy were devoted to the whole system, both in
surveying and further exploration. The maypole was used to look at a
high level in Samoreli. Numerous trips were made to look for a
possible sink; although several caves were discovered or shown to us,
no penetrable sink could be found. Further important discoveries were
made towards the end of the expedition when we were effectively
without transport. A short cave was discovered which led to the Pozo
del Molino. The entrance series to Fuentica proved to he enormously
complex new routes were discovered each time a party went into that
entrance. Two days before departure a further series of large passages
in the stream way beyond the downstream sump were entered and a second
large chamber was discovered.

This whole system is therefore very extensive and will probably yield
more passage to further exploration, though we feel that we have
managed to explore the bulk of it. A fuller a description and the
survey of the system will be included in the final report.

One other cave occupied almost as much of the expedition's attention,
in theory rather than practice, since it is 25 kilometres from Rales.
The Cueva Orandi is very well known to Oxford expeditions. It is
situated some 270 metres above and about 1 kilometre behind the
resurgence at the shrine of Covadonga, for which it is the probable
sink. The volume of water sinking in the cave is not as considerable
as that resurging, but nevertheless, sufficient to make the cave
extremely hazardous. The sink was first explored by the 1961 Oxford
expedition who reached a reported depth of 75 metres. The 1972
reconnaissance party went as far as the climb at the foot of the 20
metre pitch. Only vague reports were to be had as to what happened
beyond this point. Our first trip was unduly curtailed by a serious
mishap - one of the party falling 8.5 metres, fortunately without
serious injury. Later trips showed that we would not have been able
to go much further in any case since the cave was taking more water
than usual. Two more trips were made to Orandi. The first involved
exploration down to the sump at approximately 100 metres via 4
pitches, three of them wet. The passage beyond the pitches descends
just as steeply in a series of interconnected potholes, most aptly
described by one of the party as being like a slab of Gruyere cheese,
set at an angle of 30 degrees. The sump is not immediately
bypassable, but a large oxbow leads to an estimated 5 metre pitch
which was not descended. The survey, which has just been drawn up,
shows that the chance of a bypass is more or less assured, in so far
as any statement of certainty can be made about this cave. It was
intended to push this bypass on the surveying and detackling trip, but
the pushing party somehow contrived to be never more than 20 metres in
front of the surveyors and did not descend the pitch. This cave is
extremely dangerous since its drainage area is very extensive. Flood
debris is a constant reminder that one would have to have the cave
very rapidly in the event of a storm. Nevertheless, there is a good
chance that a through trip would be possible, though impolitic in view
of the esteem with which the resurgence is regarded.

The main hope of the expedition, the Negra polje, did not live up to
expectation. The actual cave, the Cueva Negra, has a surveyed length
of 600 metres, and is a very fine cave whilst it lasts. It is
essentially a meandering stream massage in the best tradition of
Yorkshire caves, punctuated by two pitches. The limit of exploration
was a tight flooded rift, which could be forced by divers, or indeed
by a caver with a snorkel and a strong death wish. Another short cave
(Cueva Lledales) of about 100 metres, in length was investigated,
being adjacent to Negra. No other caves were discovered in the
vicinity, which in view of the severity of the march to the polje was
a relief to several members of the expedition.

Several trims were made to the area of the Cueva de Tinganón, above
Ribadesella. A large number of photographs were taken in Tinganón, but
since a survey of the cave was of low priority, it was not surveyed.
The adjacent Abseil Cave, whose name has not been discovered, was
explored and surveyed, bit yielded little in the way of new passage.
This cave contains a number of fine decorations, particularly in the
high level passage above the sump. The sump itself, artificially
extended by a dam is a variable quantity. On the surveying trip it
proved to have shrunk by 16 metres.. Records have been left by
previous visitors, the earliest being October 1916.

The expedition also spent a considerable amount of time in the area of
Mestas - Socueva, investigating the valley of the Piedra Hita and the
surrounding hills, but finding little of significance. Several small
caves were discovered or shown to us by the villagers. The cueva del
Agua at Mestas was the scene of serious but unsuccessful sump pushing
trip, so that the total cave length remains at 31 metres. The Cueva
del Agua at Socueva managed to elude our searches, as did the
reportedly bottomless holes above Mestas. The villagers are only too
happy to lead cavers to these caves, but whether anyone would be
capable of going down them after such a walk is another matter.

Some time was devoted to the area of Ardisana - Mere, and the valley
of the Rio Blanco o caves of any consequence were discovered, but was
found that some revision in needed to make the geological map more
accurate.

The whole area around Rales was very thoroughly investigated. Several
small caves were located. At the time, we were inclined to pay little
attention to these since they did not go anywhere. However, the newest
discoveries in Fuentica cast new light on several of these caves,
particularly those above the blocked downstream resurgence.

Several trips were made to the Caldueño valley for the benefit of
those who had not been present on the previous expeditions based at El
Mazuco. A certain amount of time was spent in the Rotella - Villa area
which lies between Rales and Cortines; two potholes were entered which
proved to be rather short.

Despite fears beforehand, the expedition found itself with more than
sufficient tackle to cope with all the caves which were investigated.
The vehicle problem was more acute. The original plan had been to take
two vehicles to Spain, but this proved to be impossible for financial
reasons. The expedition was therefore dependent upon the single
vehicle, which performed admirably under the circumstances. However,
with eight as the average number, it was not always possible to allow
everyone to pursue their own inclinations. Four days were spent
without the car when it developed a major hydraulic leak and we had to
wait for a delivery of fluid from Madrid. We were fortunate therefore
that the Rales system proved to be far more extensive than appeared at
first sight. Nevertheless, it is strongly recommended that any future
expedition should try to have two vehicles available if it is at all
possible financially.

Two days before we left Rales, a party drove to the area between
Infiesto and Campo de Caso to make a cursory examination of the little
known region of limestone there, which despite its close proximity to
Oviedo, does not seem to have been subject to the attentions of
speleologists. Several cave entrances were located from the road. The
nature of the terrain is promising; tentative plans have been made to
send a small reconnaissance expedition to the area next summer in
order to look more closely into its potential.

The full report of the 1973 expedition, including surveys, photographs
and a geological report, will appear in due course. It will be sent
out at the earliest opportunity.
See Proc OUCC (7).